Mechanical marking instrument



Feb. 16, 1965 w. B. SPATZ MECHANICAL MARKING INSTRUMENT Filed July 13.1961 United States Patent 3,169,511 MECHANICAL MARKING INSTRUMENT WalterB. Spatz, Los Angeles, Calif, assignor to Spatz Corporation, SantaMonica, Calif, a corporation of California Fiied'July 13, 1961, Ser. No.123,679 4 Claims. (Cl. 120-18) The present invention relates to markinginstruments and more particularly to mechanically actuated devicesadapted to contain lead, crayon, brushes, scribers, and the like.

Mechanical pencils have been provided embodying a screw-type feed foradvancing and retracting the lead or crayon embodied therein. The screwfeed parts of such pencils have been made of metal, which are relativelydifiicult and costly to manufacture. Moreover, such pencils have beencomposed of a comparatively large number of parts, adding to theircomplexity and cost of manufacture. In many types of mechanical pencils,the lead or crayon is subject to torque resulting from relative turningof the pencil parts to secure longitudinal movement of the lead orcrayon, which has the obvious disadvantage of inducing breaking of thelead or crayon.

An object of the present invention is to provide a mechanical markinginstrument of the screw feed type capable of advancing and withdrawing amarking element, possessing comparatively few parts, which arerelatively easy and economical to manufacture and assemble.

Another object of the invention is to provide a mechanical markinginstrument of the screw feed type in which all of the parts can beproduced, if desired, by a molding operation in an inexpensive manner,as by making them of a suitable synthetic resin, none of the workingparts being made of metal.

A further object of the invention is to provide a mechanical markinginstrument of the screw feed type capable of advancing and retracting amarking element by relatively turning parts of the instrument, in whichthe marking element is not subject to the torque incident to relativeturning of the parts.

This invention possesses many other advantages, and has other objectswhich may be made more clearly apparent from a consideration of a formin which it may be embodied. This form is shown in the drawingsaccompanying and forming part of the present specification. It will nowbe described in detail, for the purpose of illustrating the generalprinciples of the invention; but it is to be understood that suchdetailed description is not to be taken in a limiting sense, since thescope of the invention is best defined by the appended claims.

Referring to the drawings:

FIGURE 1 is a longitudinal section through a mechanical markinginstrument embodying the invention, parts being shown in side elevation,and with the marking element, such as a crayon, fully retracted withinthe barrel of the instrument;

FIG. 2 is a view similar to FIG. 1, illustrating the marking elementadvanced or propelled forwardly of the instrument;

FIG. 3 is an isometric view of the rear portion of the driver or feedmember of the instrument;

FIG. 4 is an enlarged longitudinal section taken along the line 44 onFIG. 2;

FIG. 5 is a cross-section taken along the line on FIG. 4;

FIG. 6 is a cross-section taken along the line on FIG. 1.

The mechanical writing instrument illustrated in the drawings includesan elongated barrel 1!) comprising a magazine or forward barrel section11 and a rear barrel section 12. The forward barrel section terminatesin a rounded nose 13 and has a noncircular bore 14 therethrough, whichfor example, may be pentagonal in crosssection; The rear portion 15 ofthe forward section is provided with a counterbore 16 receiving theforward, reduced diameter portion 17 of the rear barrel section 12. Theinner end of the counterbore 16 provides a stop shoulder 18 adjacent tothe forward end of the rear barrel section 12.

The'forward and rear barrel sections 11, 12 can be turned with respectto each other, but are prevented from moving longitudinally. Such actionis provided by a swivel connection between the parts. As disclosed, theforward barrel section 11 has an internal circumferential rib 19 fittingwithin a companion external circumeferential groove 20 in the rearbarrel section 12.

The rear barrel section has an internal thread or screw element 21extending from its forward end 22 and terminating in a rear stopshoulder 23. Disposed within the rear section is a follower, feed memberor driver 24, consisting of an elongate shank portion 25 and a rear headportion 26 provided with diametrically opposed longitudinal slots orgrooves 27,. the sides 28, 29 of each groove being spaced apart so as toallow the inclined internal thread 21 to pass through the groove. Oneface 30 of the thread will engage a rear end 31 of a groove side 28;whereas, the opposite face 32 of the thread will engage the forward end33 of the opposite side 29 of the groove. The sides 28, 29 of the grooveare so shaped that substantially the full lateral extent of each end 31,33 of the groove engages its companion face 30, 32 of the thread along aline of contact, in order to distribute the load along such line ofcontact.

The head 26 of the driver 24 is substantially larger in lateral extentthan its elongate shank 25. The shank is of noncircular cross-section,conforming to the shape of the non-circular bore 14 in the forwardbarrel section 11. If the bore in this latter section is pentagonal,then the cross-section of the driver shank 25 will also be pentagonal,the driver shank at all times extending into the pentagonal bore 14 ofthe forward section so that the two parts are keyed to one another, withthe driver capable of moving longitudinally within the pentagonal bore.In effect, thedriver 24 is slidably splined to the forward, barrelsection 11 and is prevented from rotating relative thereto.

The driver 24 is adaptedto occupy a rear position within the rear barrelsection 12 with the rear end 35 of its head engaging the stop shoulder23 in the rear barrel section adjacent to the end of its internal thread21. At this time, the forward end portion 36 of the driver is stillextending into the pentagonal bore, as disclosed in FIG. 1. Upon turningthe rear barrel section 12 and driver 24 in the proper direction withrespect to each other, the threaded engagement between the head 26 andthe internal thread 21 will cause the driver 24 to advance inthe-barrel, the extent of forward feeding or advancing being limited byengagement of the forward end 37 of the head with the counterboreshoulder 18 of the forward section 11, which acts as a stop.

T o prevent unthreading of the head 26 from the in ternal thread 21 ofthe rear barrel section 12, when the driver 24 is in its forwardmostposition, the head end 37 projects forwardly beyond the forward end 33of the groove side 29 that contacts the face 32 of the thread, so thatthe forward end 37 of the head engages the stop shoulder 18 with thethread 21 still fully meshed with the opposed ends 31, 33 of the groovesides. To allow the thread 21 to pass through the groove 27, the lattermerges into an enlarged groove 27a, the groove 27, 27a being of thestepped configuration illustrated in the drawings. In View of the smalldimensions of the parts, the making of the driver head 26 only of thelength of the short side 29 of the groove 27 might result in inadvertentcomplete unthreading of the head from the forward end of the thread 21when the driver 24 is in its fully advanced position. By making the head26 of a greater length, and with the stepped groove 27, 27a, the ends31, 33 of the sides of the groove will remain in contact with the threadrearwardly of the forward end 22 of the thread when the driver is in itsforwardmost position, and with the forward end 37 or" the head engagingthe stop shoulder 18 at the inner portion of the counterboreof theforward barrel section 11. The extended or greater length of the driverhead 26 also enhances the stability of the driver 24 in movinglongitudinally Within the rear barrel section 12.

As disclosed in the drawings, the driver 24 can advance or retract acrayon or pencil 50 connected thereto. This crayon or pencil preferablyhas the same configuration as the bore 14 of the forward barrel section,with suitable operating clearance therebetween. In the example shown,since the bore 14 is pentagonal in shape, the crayon or pencil t) willhave a corresponding shape. Its forward end 51 is formed as a point andits rear end 52 is of reduced diameter, providing a cylindrical portionadapted to frictionally. fit within a companion cylindrical bore orsocket 53 in the forward end of the driver, in order to releasablycouple the pencil to the driver. If desired, the pencil or crayon 50 maybe suitably attached to an adapter 54 of non-circular or pentagonalcross-section, which has the reduced diameter portion 52 piloted withinthe forward socket 53 of the driver 24, and making a friction fit withthe socket wall. The adapter 54 and pencil 50 preferably do not have anygreater lateral dimension than the driver shank 25, so that torque istransmitted between the forwardbarrel section 11 and the driver, and notbetween the adapter 54 or crayon 50 and the forward barrel section.

The marking instrument consist of only three parts,

the forward barrel section 11, the rear barrel section 12, and thedriver or follower 24. If desired, each of these parts may be made ofseveral pieces secured together, but, essentially, the instrumentconsist of the three relatively movable parts above named. These threeparts can be made economically and rapidly by molding them of a suitablesynthetic resin, such as styrene. The threads 21 are easily molded inthe rear barrel section 12, and the driver head 26, which is to meshwith the internal thread 21, is also readily molded, the longitudinalsides 28, 29 of each groove 27, including the side 29a of the stepped orenlarged groove portion 27a, preferably being substantially parallel tothe axisof the driver, to facilitate its molding and its easy removalfrom the mold. The circumferential groove 20 receiving the rib 19, andwhich forms the swivel connection between the forward and rear barrelsections 11, 18, may be formed in the reduced diameter or forwardportion 17 of the rear barrel section 12 after the latter has beenremoved from the mold.

In assembling the instrument, the driver head 26 is inserted into theforward portion of the rear barrel section and placed in appropriatemesh with the internal thread 21, being turned to feed rearwardly withinthe barrel section 12. The forward barrel section 11 is then placed overthe reduced diameter portion 17 of the rear barrel section, the forwardend 22 of the rear barrel section engaging the rib 19. Upon exertion ofa sufiicient endwise force, the rib 19 is deflected outwardly slightly,or the forward portion of the rear barrel section is deflected inwardlysufiiciently, so that the rib 19 snaps over the end 22 of the rearbarrel section and then retracts inherently into the circumferentialgroove 29. This can occur because of the fact that the styrene, or otherplastic material, of which the parts are made has suflicientelasticity.- The forward and rearward sections 11, 12 are therebyswivelly connected to one another, their relative longitudinal movementbeing prevented, but their relative rotation or turning being permitted.

The driver or follower 24 is in the pentagonal bore 14 of the forwardsection 11. Up'on relative turning of the rear barrel section 12 withrespect to the driver 24 and the forward barrel section 11, the driveris fed in a forward direction until its socket 53 is adjacent to theforward end 13 of the barrel. A crayon or pencil 50 can then be insertedin the driver socket 53, whereupon the rear barrel section 12 is turnedin the opposite direction 1 relative to the forward barrel section 11and the driver 24 to retract the latter and the pencil 59 within thebarrel, the extent of retracting being limited by engage ment of thedriver head 26 with the rear stop shoulder 23. The extent of forwardfeeding of the driver is limited by engagement of the forward end 37 ofthe driver head with the stop shoulder 18 at the inner end of thecounterbore 16. When the driver head engages the rear stop shoulder 23,the crayon or pencil 50 is preferably disposed completely within thebarrel (FIG. 1). When the crayon or pencil is to be advanced orpropelled, the rear barrel section 12 need only be turned relative tothe forward barrel section 11 and driver 24 a partial revolution toexpose the pencil or crayon to the desired extent. Partial turning isonly required, since the internal thread 21 preferably has a relativelysteep pitch, and, in fact, it may be a multiple or double pitch thread.The relatively steep angle of the thread 21, which, for example, may beabout 45 degrees and the use of a multiple pitch thread enables a singlemovement of a persons wrist to fully advance the driver 24 within thebarrel and also fully retract the driver within the barrel, which, ofcourse, will also fully advance or retract the crayon or pencil 5i)releasably coupled thereto. With the driver 24 in its fully advancedposition within the barrel, the pencil or the portion of the pencilremaining may be removed from the socket 53 and a replacement pencil orcrayon substituted for it, after which the driver and pencil areretracted within the barrel.

It is desirable to avoid imposing torque on the crayon or pencil,particularly when soft crayon is used, such as in connection with theuse of the instrument as an eyebrow applicator. In the present case, thetorque incident to relative turning of the parts to advance or retractthe driver 24 and pencil or crayon 51) is not imposed on the latter,since it is the driver which is slidably splined to the forward barrelportion 11, and not the crayon or pencil. The crayon or pencil couldassume any desired cross-sectional shape, preferably being made of across-section to conform to the shape of the bore 14 in the barrel sothat the quantity of material in the crayon or pencil can be at amaximum.

Although described specifically in connection with a crayon or pencil,the instrument can be used in connection with other elements. Forexample, the part 50 may be a scriber having a scribing point 51, or itmay be constituted as a brush in which the forward portion 51 has.suitable bristles.

I claim;

1. In a mechanical marking instrument: forward and rearward barrelsections piloted one within the other and rotatable relative to eachother; said rearward section having an internal thread extending from arear portion of said rearward section to its forward end; said forwardsec-- tion having a non-circular bore; .and a driver having a shankportion of non-circular cross-section conforming to said non-circularbore and longitudinally slidable in said here and a head at the rear ofsaid shank portion having a longitudinal groove therein receiving saidinternal thread, said thread engaging opposite sides of said groove,whereby relative turning between said sections feeds said driverlongitudinally along said rear section and said bore, said shank portionhaving means at its forward end for engagement with a companion markingelement; said head having a forward portion provided with a recessthrough which said thread extends freely and extending forwardly of theforward point of engagement between said thread and one side of saidgroove and adapted to engage said forward section to limit forwardmovement of said driver in said sections and to prevent compieteunthreading of said head from said thread.

2. In a mechanical marking instrument: forward and rearward barrelsections piloted one within the other and rotatable relative to eachother; said rearward section having an internal thread extending from arear portion of said rearward section to its forward end; said forwardsection having a non-circular bore; a driver having a shank portion ofnon-circular cross-section conforming to said non-circular bore andlongitudinally slidable in said bore and a head at the rear of saidshank portion having a longitudinal groove therein receiving saidinternal thread, said thread engaging opposite sides of said groove,whereby relative turning between said sections feeds said driverlongitudinally along said rear section and said bore, said shank portionhaving means at its forward end for engagement with a companion markingelement; stop means on said rearward section engageable by said head tolimit rearward movement of said driver in said sections; said headhaving a forward portion provided with a recess through which saidthread extends freely and extending forwardly of the forward point ofengagement between said thread and one side of said groove and adaptedto engage said forward section to limit forward movement of said driverin said sections and to prevent complete unthreading of said head fromsaid thread.

3. In a mechanical marking instrument: forward and rearward barrelsections piloted one within the other and rotatable relative to eachother; said rearward section having an internal thread extending from arear portion of said rearward section to its forward end; said forwardsection having a non-circular bore; a driver having a shank portion ofnon-circular cross-section conforming to said non-circular bore andlongitudinally slidable in said bore and a head at the rear of saidshank portion having a longitudinal groove therein receiving saidinternal thread, said thread engaging opposite sides of said groove,whereby relative turning between said sections feeds said driverlongitudinally along said rear section and said bore, said shank portionhaving means at its forward end for engagement with a companion markingelement; stop means on said rearward section engageable by said head tolimit rearward movement of said driver in said sections; said headhaving a forward portion extending forwardly of the forward point ofengagement between said thread and one side of said groove and adaptedto engage said forward section to limit forward movement of said driverin said sections and to prevent complete unthreading of said head fromsaid thread; said forward portion of said head having a second grooveextending from and substantially wider than said other groove andthrough which said thread extends.

4. In a mechanical marking instrument: a forward barrel section having anon-circular bore therethrough and a generally cylindrical counterboreproviding an end wall; a rearward barrel section piloted within saidcounterbore; one of said sections having a circular rib received withina circular groove in the other of said sections to couple said sectionslongitudinally together while permitting their relative rotation; saidrearward section having an internal thread extending from the forwardend of said rearward section to a rear portion thereof; a driver havinga shank portion of non-circular cross-section conforming to saidnon-circular bore longitudinally slidable in said bore and a head at therear of said shank portion having a longitudinal groove thereinreceiving said internal thread, said groove being defined by opposedsides parallel to the axis of said driver engaged by said thread,whereby relative turning between said sections feeds said driverlongitudinally along said rear section and said bore'; said shankportion having means at its forward end for engagement with a companionmarking element; stop means on said rearward portion engageable by saidhead to limit rearward movement of said driver in said sections; saidhead having a forward portion extending forwardly of the forward pointof engagement between said thread and one side of said groove andadapted to engage said end wall to limit forward movement of said driverin said sections and to prevent complete unthreading of said head fromsaid thread, said forward portion of said head having a second grooveextending from ahd sub stantially wider than said other groove andthrough which said thread extends.

References Cited in the file of this patent UNITED STATES PATENTS

1. IN A MECHANICAL MARKING INSTRUMENT: FORWARD AND REARWARD BARRELSECTIONS PILOTED ONE WITHIN THE OTHER AND ROTATABLE RELATIVE TO EACHOTHER; SAID REARWARD SECTION HAVING AN INTERNAL THREAD EXTENDING FROM AREAR PORTION OF SAID REARWARD SECTION TO ITS FORWARD END; SAID FORWARDSECTION HAVING A NON-CIRCULAR BORE; AND A DRIVER HAVING A SHANK PORTIONOF NON-CIRCULAR CROSS-SECTION CONFORMING TO SAID NON-CIRCULAR BORE ANDLONGITUDINALLY SLIDABLE IN SAID BORE AND A HEAD AT THE REAR OF SAIDSHANK PORTION HAVING A LONGITUDINAL GROOVE THEREIN RECEIVING SAIDINTERNAL THREAD, SAID THREAD ENGAGING OPPOSITE SIDES OF SAID GROOVES,WHEREBY RELATIVE TURNING BETWEEN SAID SECTIONS FEED SAID DRIVERLONGITUDINALLY ALONG SAID REAR SECTION AND SAID BORE, SAID SHANK PORTIONHAVING MEANS AT ITS FORWARD END FOR ENGAGEMENT WITH A COMPANION MARKINGELEMENT; SAID HEAD HAVING A FORWARD PORTION PROVIDED WITH A RECESSTHROUGH WHICH SAID THREAD EXTENDS FREELY AND EXTENDING FORWARDLY OF THEFORWARD POINT TO ENGAGEMENT BETWEEN SAID THREAD AND ONE SIDE OF SAIDGROOVE AND ADAPTED TO ENGAGE SAID FORWARD SECTION TO LIMIT FORWARDMOVEMENT OF SAID DRIVER IN SAID SECTIONS AND TO PREVENT COMPLETEUNTHREADING OF SAID HEAD FROM SAID THREAD.